Study On Cross-track Velocity Ambiguity Resolution For SAR Moving Targets

Synthetic Aperture Radar (SAR) has been widely used in many military and civilian applications. With the increasing requirement in military and civilian areas, it is highly desirable to detect moving targets and relocate them. The key procedure of target relocation is the parameter estimation. Cross-track velocity is a very important parameter. This dissertation deals with the resolution of Doppler ambiguity of cross-track velocity of grounding fast moving target estimation.We first analyze the model of stationary target echoes and that of moving target, and discuss the effect of moving target on the echoes and the SAR image. Then aiming to cross-track velocity ambiguity caused by fast moving of the grounding target, we discuss a algorithm based on two-looking data to estimate the unambiguous cross-track velocity and give analysis of the experimental results. Finally a Doppler ambiguity number estimate algorithm is discussed. Because of the relation between the slant range and the Doppler ambiguity number of the grounding moving target, we can estimate the Doppler ambiguity number by correcting the range cell migration. Experimental results show that the ambiguity number of the cross-track velocity can be accurately estimated.